Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:astro-ph/0609387)
· References in the article
· Citations to the Article (10) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (18)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Radio observations of candidate magnetic O stars
Authors:
Schnerr, R. S.; Rygl, K. L. J.; van der Horst, A. J.; Oosterloo, T. A.; Miller-Jones, J. C. A.; Henrichs, H. F.; Spoelstra, T. A. Th.; Foley, A. R.
Affiliation:
AA(Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands ), AB(Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands), AC(Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands), AD(ASTRON, 7991 PD, Dwingeloo, The Netherlands), AE(Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands), AF(Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands), AG(ASTRON, 7991 PD, Dwingeloo, The Netherlands), AH(ASTRON, 7991 PD, Dwingeloo, The Netherlands)
Publication:
Astronomy and Astrophysics, Volume 470, Issue 3, August II 2007, pp.1105-1109 (A&A Homepage)
Publication Date:
08/2007
Origin:
EDP Sciences
Keywords:
stars: magnetic fields, stars: early-type, stars: general, stars: mass-loss, radio continuum: stars, radiation mechanisms: non-thermal
DOI:
10.1051/0004-6361:20066299
Bibliographic Code:
2007A&A...470.1105S

Abstract

Context: Some O stars are suspected to have to have (weak) magnetic fields because of the observed cyclical variability in their UV wind-lines. However, direct detections of these magnetic fields using optical spectropolarimetry have proven to be very difficult.
Aims: Non-thermal radio emission in these objects would most likely be due to synchrotron radiation. As a magnetic field is required for the production of synchrotron radiation, this would be strong evidence for the presence of a magnetic field. Such non-thermal emission has already been observed from the strongly magnetic Ap/Bp stars.
Methods: We have performed 6 and 21 cm observations using the WSRT and use these, in combination with archival VLA data at 3.6 cm and results from the literature, to study the radio emission of 5 selected candidate magnetic O stars.
Results: Out of our five targets, we have detected three: ξ Per, which shows a non-thermal radio spectrum, and α Cam and λ Cep, which show no evidence of a non-thermal spectrum. In general we find that the observed free-free (thermal) flux of the stellar wind is lower than expected. This is in agreement with recent findings that the mass-loss rates from O stars as derived from the Hα line are overestimated because of clumping in the inner part of the stellar wind.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints